The present invention relates generally to telecommunication systems and more particularly to a test unit for use at a network interface device, including long distance lines, local lines and subscriber equipment.
The United States Public Switched Telephone Network (PSTN) includes a number of different components. Each of these components was originally under the ownership and control of a single telephone service provider. Currently, however, respective components in the PSTN may be owned and/or under the responsibility of different parties. For example, a long distance telephone company may be responsible for long distance lines, whereas a local telephone company may be responsible for local lines, and a subscriber may be responsible for equipment at the subscriber premises.
When a malfunction in the PSTN arises, it is necessary to identify whether the malfunction is due to a problem located at the subscriber premises, in the subscriber loop or in the network of a chosen service provider. Responsibility for correcting the problem lies with the party responsible for the component where the problem lies. Matters are complicated by multiple service providers competing for local telephone communication services. As a result, the subscriber loop may be owned and maintained by one company yet leased by another company that provides local services to subscribers. Hence, each local service provider needs a way to immediately test for proper functioning of the network as far as a network interface device (NID). The NID is positioned at the DEMARC, i.e., the demarcation point where a local telephone company responsibility stops and the subscriber responsibility begins. Typically, the NID is located either adjacent to a subscriber""s premises or a short distance away from the subscriber""s premises. Thus, there is a need to be able to determine the location of a problem within the PSTN without incurring significant overhead and without suffering substantial delay.
The present invention addresses limitations of the conventional system by providing a remotely activated test unit at a NID. The test unit can perform a number of different tests to identify malfunctions and to determine the location of problems. For example, the test unit may be able to generate tones, silence a line and identify latency for transmitted signals. The test unit may be remotely activated to eliminate the need for sending maintenance personnel out to the NID.
In accordance with one aspect of the present invention, a component for testing a portion of a network is provided in a NID. The component includes a testing module for performing testing on a portion of the network as well as an activation module for activating the testing module to perform the testing. The activation module includes a remote activator for remote activation. The remote activator may take the form of a tone detector for detecting a characteristic tone or a radio frequency detector for detecting at least one characteristic radio signal for activating the testing module. The testing module includes a tone generator for generating a test tone. In addition, the testing module includes a silencing element for silencing a portion of the network of a loop-back element for echoing signals over a portion of the network.
In accordance with a further aspect of the present invention, a system is provided in a communications network that provides communications with customer premises. A network includes a local exchange carrier wiring and customer premises. The system also includes a testing device for testing a portion of the network terminating at the NID.
In accordance with an additional aspect of the present invention, a test unit is positioned at a NID within a communications network. The NID is in proximity to subscriber premises. The test unit is operative to test at least a portion of the communications network. The test unit includes at least one element for initiating such a test.
In accordance with a further aspect of the present invention, a communications network includes a NID. Tests are performed with a test unit at the NID to determined whether the communications network is running properly and whether any problems exist in the communications network.